Decision-feedback differential demodulation of bit-interleaved coded MDPSK

A novel simple receiver structure for M-ary differential phase shift keying (MDPSK) transmission over flat Rayleigh fading channels without channel st ate information is proposed. Convolutional codes are used For error correct ion and bit-interleaving as an appropriate means to combat the effects of f ading, and the hard decisions of the Viterbi algorithm are fed back during the decoding process in order to improve the calculated bit metric. Iterati ve decoding with this decision-feedback differential demodulation (DF-DM) r esults in significant power efficiency gains compared to those achieved usi ng conventional differential demodulation, while the computational complexi ty remains low.